Claude Environment Settings Guide: Timezone, Language and Real-Address Leaks

If the Claude Environment Check flags items such as "System timezone", "System language" or "Real network address leak", this guide walks you through fixing them one by one.

Two notes before you start:

• Claude is only offered in supported countries and regions, and Anthropic's policy is about where you are actually located (Supported Regions Policy). This guide is about making your device settings match where you actually are and stopping your browser from leaking your address. It is not a way around Anthropic's regional restrictions or terms. If you're in an unsupported region, see using Claude through a relay site.
• Menu names differ between systems, brands and versions. Treat the paths below as a guide and follow what your device actually shows. These settings only lower risk; use them as a reference.

1. System timezone

Websites can read your computer's or phone's timezone. It should match where you actually are. The most common case is moving abroad to study, work or travel while your device stays on your home time zone, or turning off automatic time zone once and forgetting to turn it back on. The fix is simple: turn on automatic time zone so your device follows your location, or pick the city where you actually are.

macOS

1. Open the Apple menu and choose System Settings.
2. Select General in the sidebar, then Date & Time.
3. Turn on "Set time zone automatically using your current location" (wording varies slightly by version; Location Services must be allowed).
4. If you'd rather not use location, turn it off and type the city where you actually are into "Closest city", then select it.

On older macOS (Monterey and earlier), go to System Preferences > Date & Time > Time Zone, and click the lock in the corner to make changes.

Windows 11

1. Press Win + I to open Settings.
2. Go to Time & language > Date & time.
3. Turn on "Set time zone automatically".
4. If it picks the wrong zone, turn it off and choose the time zone where you actually are from the "Time zone" drop-down.

Windows 10 uses almost the same path: Settings > Time & Language > Date & time.

iPhone / iPad

1. Open Settings > General > Date & Time.
2. Turn on "Set Automatically".
3. To set it manually instead, turn that off, tap Time Zone, then type and select the city where you actually are.

Android

Settings vary a lot between brands. The steps below are for stock Android; follow what your phone shows:

1. Open Settings > System > Date & time.
2. Turn on "Set time zone automatically". Some phones call it "Use network-provided time zone" or have a separate "Use location to set time zone".
3. To set it manually instead, turn that off, tap Time zone, pick a region, then the time zone where you actually are.

If you can't find it, search for "time zone" in the search bar at the top of Settings.

After changing the timezone, quit the browser completely, reopen it and run the check again.

2. System and browser language

Websites can see the "preferred language" your browser sends, and your system language. Language is a personal preference, and using Chinese or any other language is perfectly fine; plenty of people abroad do. The language item in the check is only a hint, and there's no need to change it for the check.

If you do want to change which language websites show you first, use the built-in system and browser settings rather than "language switcher" extensions. Some of them only change part of what the browser reports, so the browser ends up contradicting itself, and the check's "Browser language setting" item will flag the mismatch.

System language

• macOS: System Settings > General > Language & Region. Add a language under Preferred Languages, drag it to the top, and restart when prompted.
• Windows 11: Settings > Time & language > Language & region. Pick it under "Windows display language" and sign out for it to take effect. You can also adjust "Country or region" on the same page.
• iPhone / iPad: Settings > General > Language & Region > iPhone Language (iPad Language on iPad).
• Android: Settings > System > Languages (some brands say "Languages & input"), then move your language to the top. Follow what your phone shows.

Chrome and Edge

• Chrome: three-dot menu > Settings > Languages, or go to chrome://settings/languages. Add a language under "Preferred languages", click the three dots next to it and choose "Move to the top".
• Edge: three-dot menu > Settings > Languages, or go to edge://settings/languages. Move the language you want to the top of "Preferred languages".

Websites mainly read the language at the top of the list.

Firefox

Open the menu (three lines) > Settings > General. In the Language section, click the "Choose…" button for your preferred website languages, add a language and move it to the top. Wording varies slightly by version.

Safari

Safari has no language setting of its own; it follows the system language. On a Mac, to change it for Safari only, go to System Settings > General > Language & Region, click "+" under Applications, and choose Safari and a language. On iPhone and iPad, Safari follows the device language.

3. Stop your browser from revealing your real address

Browsers include a feature called WebRTC, which websites use for voice and video calls. It can sometimes bypass your proxy and reveal your local, real network address to the page. If the check reports a real network address leak, use the steps below. The most thorough fix is section 4, letting your proxy client take over all traffic; you can do both.

Chrome and Edge

1. Open the Chrome Web Store and search for "WebRTC Network Limiter". Make sure the developer is Google, then click "Add to Chrome".
2. Open its options: go to chrome://extensions, find the extension, click Details, then "Extension options".
3. The options page is in English. Select the option mentioning "Disable non-proxied UDP", meaning connections that don't go through your proxy are not used. Exact wording may differ slightly.
4. Edge users: when you open the Chrome Web Store, Edge asks whether to allow extensions from other stores. Allow it, install the extension and follow the same steps; the extensions page is edge://extensions.

With this on, voice and video calls in web pages may become slower or fail to connect. Switch back to the default option temporarily when you need them.

Firefox

1. Type about:config in the address bar, press Enter and click "Accept the Risk and Continue".
2. Search for media.peerconnection.ice.default_address_only and double-click it to set it to true. The browser then uses only your default connection and doesn't expose other network addresses.
3. If you never make video calls in the browser, you can instead search for media.peerconnection.enabled and set it to false to turn the feature off entirely. The trade-off is that web-based video meetings and voice calls will stop working.

Step 2 only reduces exposure. If your proxy isn't taking over all traffic, your real address may still be visible, so also follow section 4 and run the check again afterwards.

Safari

Safari is fairly strict about these connections by default: unless a site has camera or microphone permission, it generally won't reveal your device's local network address, so usually nothing needs changing. Your real network exit can still show if your proxy isn't taking over all traffic, though, so go by the check result and follow section 4 if it flags a leak. Also, don't grant camera or microphone access to sites you don't know.

4. Let your proxy client take over all traffic

Many proxy clients only handle traffic that follows the system proxy setting by default. Voice and video connections in the browser, and apps that ignore the system proxy setting, may go straight out through your local network and reveal your real address.

The fix is to turn on the mode in your proxy client that takes over all traffic. Common names include "TUN mode", "virtual network adapter" and "enhanced mode"; the exact name depends on your software.

• Turning on "system proxy" or switching to "global" usually isn't enough. "Global" normally just sends every website through the proxy; it doesn't mean every connection is taken over.
• Turning it on may need administrator rights or a system component; follow the prompts in your software.
• Afterwards, reopen your browser and run the check again to confirm "Real network address leak" shows OK.

If the check reports your network type as a datacenter or cloud network, your exit comes from a datacenter, which is common with VPNs and proxies. These networks are restricted more often; if you're in a supported region, using your home broadband or mobile data directly is the safer choice. We don't recommend specific providers.

After you change things

1. Run the Claude Environment Check again and confirm each result.
2. Once your settings match where you actually are, keep them stable and avoid switching network exits often.
3. Results are for reference only. They are not Anthropic's judgment and cannot guarantee your account is safe. To learn which situations cause trouble most often, read Why do Claude accounts get banned?
4. If all this feels like too much, consider using Claude through a relay site.